But in the normal course of life, our need for air is far from our thoughts, and indeed many would say that satisfying that need is the least important part of going to the filling stations. For the filling stations are the primary venue for social conversation, the places from which we draw emotional sustenance as well as physical. We all keep spare sets of full lungs in our homes, but when one is alone, the act of opening one’s chest and replacing one’s lungs can seem little better than a chore. In the company of others, however, it becomes a communal activity, a shared pleasure.